Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    1
    ReputationRep:
    Solve the equation
    x + 3 = x − 1,
    2 6
    giving your answer to 3 significant figures.

    so :x+3 and x-1 are on top of 2 and and 6
    this is a logs questions.
    I know what the answer is but I dont know gow they got it can someone explain it to me in detail. thank you
    Offline

    2
    ReputationRep:
    Is your question

     2^{x+3}=6^{x-1}?

    If so, try taking logs of both sides to get

     \log_{10}2^{x+3}=\log_{10}6^{x-1}

    Then you can use the power law to get

     (x+3) \log_{10}2=(x-1)\log_{10}6

    At which point you can multiply out, rearrange and solve (remember log 2 and log 6 are just numbers).
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What's your favourite Christmas sweets?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.